DNA Ploidy and S-phase Fraction in Breast Cancer

Lee, Chang Hwan; Lee, Young Ha; Suh, Jang Soo

Abstract

BACKGROUND: Histological differentiation, status of hormonal receptors, size of tumor, and status of axillary lymph nodes are known prognostic factors in breast cancer. Recently, the DNA ploidy and the S-phase fraction have been considered as relating to parameters affecting the prognosis of cancer patients.
METHODS
The authors measured the DNA ploidy and the S-phase fraction and evaluated their significance as prognostic factors in breast cancer. Their correlation with tumor size, lymph-node involvement, pathologic differentiation, status of hormonal receptors, menopause, and survival duration were also analyzed. The DNA ploidy and the S-phase fraction were checked with an FAC scan (Becton Dikinson, U.S.A.) and a cell fit (Becton Dikinson, U.S.A.) using the fresh breast-cancer tissue from 104 patients.
RESULTS
The ploidy analysis showed that 32% of the tumors were diploid and 68% were aneuploid. There was significance in the pathologic differentiation, but no significance in the other prognostic factors. The median S-phase fraction was 8.9%, and it was used as a cutoff point. Forty-nine percent (49%) of the tumors were greater than 8.9%, and 51% were less than it. There was significance in the status of hormonal receptors. There was no significance in the relation between these factors and the disease-free survival rate.
CONCLUSIONS
Even though these results suggest that the DNA ploidy and the S-phase fraction determined by using flow cytometry are not clinically useful independent prognostic factors, it will be necessary to measure them in a large number of patients and then follow those patients so that a multivariate survival analyses can be performed to evaluate the clinical significance of these factors.